Airplane pickup mechanism



Aug. 22 1944. w

J. G. INGRES EIAL AIRPLANE PICK-UP MECHANISM Filed May 8, 1941 4 Sheets-Sheet 2 J. G? l/vazss, H W HEY Ill) 11/ r:

U mw 1944- J. G. INGRES ETAL 2,356,671

AIRPLANE PICK-UP MECHANI SM Filed May 8, 1941 4 Sheets-Sheet 3 HWHEY Aug. 22, 1944. J, G. INGRES ETAL AIRPLANE PICK-UP MECHANISM Filed May 8, 1941 4 Sheets$heet 4 dGf/NGEEs H.W HEY Patented Aug. 22, 1944 UNi'i'E STATES TENT orsion AIRPLANE. PICKUP MECHANISM as trustees Application May 8, 1941, Serial No. 392,568

9 Claims.

This invention relates to airplane pick-up mechanisms and is an improvement over the prior patent to Henry G. Bushmeyer and Archie W. Card, No. 1,892,381, granted December 27, 1932.

In the prior patent referred to there is disclosed an apparatus for enabling an airplane to pick up packages or articles without the necessity of having to land, the mechanism generally comprising a pick-up hook suspended beneath an airplane and adapted to engage a loop in a flexible member connected to the article or package and extending across a pair of upstanding masts adapted to be swung by the pull exerted on the cable by the pick-up hook to release a latch mechanism whereby a catapult, on which the article or package rests, will be projected in the direction of travel of the airplane. This mechanism is highly advantageousin practical use for the reason that it projects the article or package to be picked up at a speed approximately equal to the speed of the plane, thus eliminating the encountering of a dead weight by the pick-up hook. Accordingly the apparatus permits the picking up with ease of articles or packages weighing many times the weight of the heaviest article or package which can be picked up from a position at rest without being pro jected in the manner stated.

The prior apparatus referred to has been found to operate perfectly for its intended purpose but involves several disadvantages. For example, the swinging of at least one of the loop-supporting masts is necessary in order to release the catapult latch mechanism, and accordingly it is necessary to employ relatively heavy expensive mast structures in order to Withstand the strain ,to which the apparatus is subjected. Moreover, it is necessary to provide substantial and relatively expensive means for supporting the masts for swinging movement. and it is necessary to provide mo- .tion transmitting mechanism between the rock shafts which carry the masts and the catapult latch in order that the latter may be released. The motion transmitting means and the rock shafts are duplicated for each mast to avoid the necessity for having to depend on the swinging movement of both masts in order to release the catapult mechanism. This duplication of parts, each relatively heavy and expensive in itself, substantially adds to the expense of manufacturing the apparatus.

An important object of the present invention is to provide a novel airplane pick-up mechanism of the type referred to wherein the use of relatively light inexpensive masts is rendered practicable because of the use of'a highly improved type of catapult latch release mechanism.

A further object is to provide such a mechanism wherein the swinging of the masts, or at least one of them, is rendered wholly unneces sary, thus eliminating the relatively expensive means previously provided for supporting the masts for swinging movement.

A further object is to provide a simpler and much less expensive means for releasing the catapult latch when the loop supported by the masts is picked up by the airplane-carried hook. A further object is to provide novel electrically controlled means for releasing the catapult mechanism when the loop in the flexible mem her to which the article or package is connected is released from either mast, thus eliminating the provision of expensive and duplicated mechanical parts for accomplishing such result. 1 I

A further object is to provide a mechanism of the type referred to wherein light and rela tively inexpensive masts may be provided-and wherein relatively inexpensive'electrical control switches may be mounted at the upper ends of the respective masts and-maintained in open position by the flexible element to which the article or package is connected,and to connect such switches to a control circuit for the catapult; latch whereby the disconnection of the flexible element from either switch upon the picking up; of the cable by the airplane carried hook will close the necessary-circuit for releasing the cata-j pult latch mechanism"whereby the article or package will be projected in the direction'of travel of the airplane to be picked up thereby without any noticeable drag on the plane.

A further object is to providean electrically controlled apparatus wherein an electrical circuit for energizing the catapult latch releasing means may be energized solely by the taking up of the slack in the flexible element connected to the article or package to be picked up.

Other objects and advantages of the invention wiil become apparent during the course of the following description.

In the drawings we have shown two embodie ments of the invention. In this showing:

the ground apparatus,

Figure 3 is an end elevation of the ground apparatus,

Figure 4 is a transverse section on line 44 of Figure 2, the article or package being removed from the catapult,

Figure 5 is an enlarged fragmentary sectional view through a portion of one of the masts and the supporting means therefor, taken substantially on line 5-5 of Figure 1,

Figure 6 is a plan view of the ground apparatus,

Figure 7 is a fragmentary detail side elevation of the upper end of one of the masts showing the switch associated therewith,

Figure 8 is a diagrammatic view showing the electrical circuits for the apparatus,

Figure 9 is a horizontal sectional view on line 99 of Figure 1,

the interior of the adjacent end or the vehicle for a purpose which will become apparent.

The vehicle is suitably supported on wheels so as to render it easily portable. In the present case, one end of the vehicle is shown as being supported by a pair of wheels 23 while the opposite end of the vehicle is provided with a caster wheel 24 having a king pin 25 rotatable in a bracket arm 26 secured against the adjacent end of the vehicle. A draft element 27 is connected to the axle of the wheel 24 so that the vehicle can be connected to a motor vehicle to be hauled Figure 10 is an enlarged fragmentary sectional 4 view ofthe Windlass taken substantially on line |0l0 of Figure 9, a

Figure 11 is a detail sectional view on line llll of Figure 9,

Figure 12 is a sectional view similar to Figure 2, partly diagrammatic, showing a modified form of the invention and the electrical circuit therefor, and, v

Figure 13 is a detail sectional view on line |3-| 3 of Figure 12, parts being omitted.

Referring to Figure 1 the numeral H3 designates an aircraft as a whole having a fuselage H below which is adapted to project an arm 12 carrying a hook l3 at its lower end connected to the lower end of a cable (not shown) extending upwardly through the arm I2 into the fuselage so that an article or package picked up by the hook l3 may be pulled upwardly into the fuselage through a suitable opening (not shown) in the bottom thereof. The particular pick-up arrangement associated with the airplane may be similar to that shown in the Bushmeyer and Card Patent No. 1,892,381 referred to above and forms no part, per se, of the present invention.

The ground portion of the mechanism comprises a vehicle indicated as a whole by the numeral M. This vehicle may be suitably constructed so as to be portable and so as to carry a catapult to be referred to,- which catapult is adapted to project the article or package to be picked up. As illustrated in the present case, the vehicle is made up of a suitable framework including channel iron rails l5 (Figures 2 and 4) extending along the bottom of the vehicle and forming the bottom of the frame thereof, these channel irons being connected by suitable end cross braces I 6 and as many intermediate cross braces I I as may be necessary for the purpose of providing rigidity.

The top frame elements of the vehicle may be in the form of longitudinal rails iii of generally T-formation turned on their sides so as to provide horizontal flanges I9 for a purpose to be described. The top and bottom frame members referred to may be connected at suitable intervals by the vertical frame members 20. At the right hand end of the vehicle as viewed in Figures 1 and 2, a relatively heavy connecting plate 2| may-be secured tothe longitudinal frame members while the opposite end of the vehicle is preferably left open for the purpose of providing access to the interior of the vehicle. The sides and bottom of the vehicle may be suitably enclosed by sheet'metal plates 22 as shown in Figure 4. One of the side plates 22 may be provided with a hand hole 22' to provide access to to and from a suitable field or to be located at different times at different points on the same field as will become apparent.

The vehicle supports a catapult mechanism through which articles or packages may be pro jected in the direction of travel of the pick-up airplane and at approximately the speed of the plane. The catapult comprises a carriage 28 in which the article or package 29 is adapted to rest and the carriage comprises a depending structure including opposite pairs ofarms 39 carrying upper and lower axles 3| and 32 on which upper and lower wheels 33 and 34 are mounted, the wheels 33 rolling upon the flanges l9 and the wheels 34 being arranged beneath the flanges l9 to act as guide wheels. The Wheels 33 and 34 operate in close proximity to the vertical portions of the frame members l8 whereby the latter act as guides to prevent any lateral deflection of the carriage 28 when the catapult operates.

The article 29 is shown in generally cylindrical form with an attaching element 35 at one end thereof. It will be apparent that the apparatus is not limited to the use of any particular type of article 29 and the latter may be in the form of a mail sack or in the form of any other package or article which it is desired to pick up. Any such article may have the attaching member 35 or a suitable eye or like device to which a flexible element 36 may be connected. This flexible element is in the form of a shock cord and from the attaching member 35 the cord 36 has two portions 3'! diverging upwardly to the tops of masts 38 and thence across between the masts as at 39 to form a loop, a portion 39 of the loop being suspended in such position as to be engaged by the airplane-carried hook I3.

It will become apparent that the present invention is not dependent for its operation on'the swinging of the masts 38 and these masts accordingl may be made as light as desired since it is not necessary that they possess any substantial structural strength. For example, bamboo poles readily may be employed as the masts, and it is preferred that some relatively inexpensive type of mast be employed so as to reduce installation and replacement costs to a minimum.

The masts 33 have their lower ends seating in sockets 40 (Figures 3 and 5) and each socket 4G is connected to a horizontal tubular member 4!. A set screw 42 may secure each mast in its socket as shown in Figure 5. is slidable in a tubular support 43 pivotally connected at its inner end as at "55 (Figure 6) to a projection 44' fixed to one side of the vehicle l4. Each support 43 and its associated tubular member occupies an extended horizontal position when the apparatus is in op eration and simple hook braces or the like 45 may be employed for holding the tubular supports in position, each of these braces being pivoted at its inner end to the Each tubular member it which may be Vehicle it as at 48 and having its other end turned downwardly toform a hook engageable in an eye 41 on the associated support 43. Each support 43 may be suitably braced by an angle brace 48 having its inner end pivoted to the vehicle as at 49 in axial alignment with the pivot 44' of the horizontal support-43. The connecting ends of the members 4'3 and may be suitably welded to each other. A setscrew 50 may be carried by the outer end of each support 43 to secure the associated tubular member 4| in adjusted position.

.To' support the vehicle and associated elements against lateral swinging when in operation, mushroom feet 5| may be employed beneath eachxmast. Each of' these feet is provided with a vertical tubular socket 52 receiving the lower end of a connecting tube 53 and fixed in vertical adjusted position with respect thereto by a wing nut 54 or the like, Each tube 53 has its upper end arranged in a socket 55 formed in the bottom of the associated socket member 40.

The power for projecting the catapult is providedf by the tensioning of a suitable shock cord 56 (Figures 2, 6 and 9). One end of this shock cord is connected to an eye 51 carried by a depending shank 58 formed integral with a longitudinally extending frame member 59 which, in turn, is formed integral at its ends with transverse frame members 60 extending between the depending wheel supports 30.

The shock cord 56 is connected by a suitable fitting B| (Figures 6 and 11) to one end of a strap or belt 62 and this strap passes around a pulley 63 mounted on a shaft 66 supported by suitable brackets carried by the lower vehicle frame members l5 (Figure 9). When the shock cord 5E'is stretched to its maximum tension the strap 62 will have been drawn up to the position shown in Figure llby means to be described.

The pulley 63 is arranged adjacent the mastend of the vehicle, remote from the catapult carried by a shaft H also supportedby the bearing bracket 68. The shaft 1! is provided with a squared end as shown in Figure 2 to be received in a socket in a suitable winding crank. Of course, power driven means may be employed for winding the strap 62 on the pulley 66. The shaft 1| carrie a ratchet wheel '52 engageable by pawl 13 spring pressed as at 14 into engagement with the teeth of the ratchet wheel. A releasing handle 15 is carried by the pawl 13 adjacent its pivot point 15 and projects beneath the vehicle but is accessible to the operator when it is desired to release the pawl from the ratchet wheel, that is, after an article or package has been projected by the catapult and picked up by the airplane, and it is desired to re-set the mechanism, as will become apparent.

Electrically controlled means is employed for releasing the latch mechanism of the catapult, this latch mechanism being shown in Figure 2. As shown, a bracket l1 carries a pivot pin 18 to support a bell crank lever indicated as a whole by the numeral 19 and comprising a long depending arm 88 and a shorter arm 8| provided with a hook 82. This hook provides a detent engageable with a hook 83 pivoted as at 84 to the catapult carriage; Accordingly it willbe apparent that the engagement of the detent 82 with the hook 83- when the shock cord 55is under tension prevents the catapult from operating until the latch mechanism is released.

A transverse member 85 extends between and is-secured to the side frame members I8 and a relatively heavy compression spring 86 is arranged between the cross member 85 and the lever arm to tend to swing this arm to a latch releasing position. Beneath the lever arm 85, a second lever arm 81 is pivotally supported as at 88 on a bracket 89 carried by a transverse member St' having its ends secured beneath the lower frame members IS; A hook 9| on one end of the lever 8'5 engages the lower end of the lever arm 80 whenthe latch mechanism is set, thus preventing the spring 86 from swinging the bell crank lever '19. A light leaf spring 9| may urge the hook 9| upwardly toward operative position. The other end of. the lever 81 is pivotally connected as at 92 to the armature 93 of a solenoid 94. This solenoid is carried by a bracket 95 se-' cured to one of the transverse frame members H as shown in Figure 2. Obviously the energizing of the solenoid releases the hook 9| from the lever arm 88 whereupon the spring 86 swings the bell crank lever 19 to the latch-releasing position.

The circuit for controlling the solenoid 94 is shown inFigure 8 and includes switches at the upper ends of the mast arm, one of these switches being shown in Figure 7. The mast switches are identical, and accordingly only one need be referred to in detail. A stationary finger 96 (Figure '7) constitutes a switch arm provided with a socket 81 adapted to be secured on the upper end of each mast 38. The upper end of the finger or switch arm 96 extends in the direction of travel of the airplane and upwardly somewhat at an angle as shown in Figures 1 and 7. A sleeve 98' surrounds and is secured to each mast 38 and carries an car 99 to which a movable finger I89, constituting a switch arm, is pivoted as at lill. A torsion spring H32 urges the switch arm I20 toward the switch arm 96 to tend to establish electrical connection therewith. The'portion 39 of the shock cord 36 which extends between the masts is preferably provided with a pair of rubber or similar thimbles Hi3 spaced apart a distance equal to the distance between the switches at the upper ends of the masts. Accordingly when the pick-up loop is set, one of the rubber thimbles I83 is arranged between the switch arms at the upper end of each mast, as shown in Figure'l. It is assumedin the present case that the masts are made of bamboo or other non-conducting material in which case the socket 9'? and the sleeve 98'vvill be insulated from each other without the use of any special insulating element.

The circuit for the switches and for the solenoid 94 is shown in Figure 8. The source of current HM, such as a storage battery, is mounted within the vehicle and has one terminal connected by a wire N35 to a switch arm iilt engage able with a contact NET, and a wire ms leads from this contact to one terminal of the solenoid The switch M36 is manually operable and is left open until the pick-up loop and its thimbles H33 are arranged in operative position ready for a pick-up operation. 1

The other terminal of the source is connected by a wire I99 to branch wires H5] and MI leading to the respective stationary switch arms 96.

The second terminal of the solenoid is connected to a wire I I2 and this wire is connected by branch wires H3 and H4 to the respective movable switches I 00. Accordingly it will be apparent that the two mast switches are in parallel with each other and that the closing of either of these switches will energize the solenoid 94.

In the form of the invention shown in Figures 12 and 13 the use of the masts for carrying switches is eliminated in favor of a single switch mounted in the vehicle. In this connection it will become apparent that either apparatus may be employed and the time lag between the pickup of the loop 39 and the projection of the article or package by the catapult will be less in the modified form of the invention than in the form previously described. Referring to Figures 12 and 13, it will be noted that the catapult latch mechanism and the means for releasing such mechanism is identical with the form previously described and the parts common to the two forms of the mechanism have been illustrated by the same reference numerals. Instead of having switch devices at the upper ends of the masts, the modified form of the invention employs a light but relatively stiff wire switch device indicated as a whole by the numeral H5 and comprising a wire bent intermediate its ends to form a loop I I6 to receive a pivot pin I I1. To one side of the loop H6 the wire is provided with an arm H8 curving upwardly and forwardly and terminating in a fork I I9 as shown in Figure 13. The fork H9 may be welded on the end of the arm H8 as will be apparent. The arm H6 is grounded as at I29.

The other end of the wire H8 is formed as an arm I2I terminating in a switch contact I22 engageable with a stationary contact I23 connected by a wire I24 to one terminal of the solenoid. The other terminal of the solenoid is connected by a wire I25 to a source I26. The other terminal of the source is connected by a wire I21 to a stationary contact I28 engageable by a manual switch I29 from which a wire I30 leads to a ground I3I.

Referring to Figure 13 it will be noted that the stationary contact I23 is carried by an arm I32 pivoted as at I33 to one of the side plates 22 of the vehicle. The arm I32 is urged upwardly by a light spring I34 seated on the end of a bracket I35 also secured to the side plate 22. An upstanding stop member I36 is carried by the arm I32 and is engageable by an adjusting screw I31 to determine the position of the contact I23 with respect to the contact I22 for a purpose to be described.

When the form of the invention shown in Figures l2 and 13 is employed the two loop portions 31 (Figure 3) of the pick-up shock cord are brought together and connected by a single cable section or shock cord I38 to the connection 35 on the article 29 to be picked up. It also will become apparent that in using this form of the invention the structure shown in Figure '7 may be employed at the upper end of each mast, but the elements will serve purely as holding devices for the rubber thimbles I03 and will not function as electric switches. As willbecome apparent, the pick-up loop section 39 will be engaged by the air-plane-carried hook I3 and the thimbles I33 (Figure '7) will be disengaged, whereupon the slack of the pick-up cord will be taken up. When this occurs the cord section I38 (Figure 12) will pull upwardly on the fork H9 to close the circuit across the contacts I22 and I23, and then will be jerked loose from the fork H3 to release the arm H8, all of this taking place substantially simultaneously with the energizing of the solenoid 94 and the releasing of the catapult latch.

In either form of the invention, the energizing of the solenoid 94 will release the catapult latch mechanism, whereupon the tensioned shock cord I9 will project the catapult and the article or package thereon in the direction of travel of the airplane, and the track formed by the flange I9 preferably slopesupwardly to a slight extent toward the discharge end of the apparatus. The vehicle is preferably provided with means for cushioning the stopping of the catapult carriage at the discharge end of the apparatus. For this purpose the forward cross member 60 (Figure 2) of the catapult carriage is adapted to engage a cap I32 (Figure 9) engaged by one end of a spring I33 having its other end arranged in a suitable housing I34 adapted to telescope with respect to the cap I32.

The operation of the form of the invention shown in Figures 1 to 11 inclusive is as follows:

The invention is particularly intended for use as a mail pick-up service for small cities and communities which have no adequate air field service, or wherein the landing of a plane for depositing and picking up mail is not justified. There are innumerable cities and communities which come within this category and which should be provided with air mail service, and the present invention provides an efficient and economical means for picking up mail without the necessity for the plane landing and then taking off.

It is intended that regular routes be established over which the planes will fly to pick up mail from regular pick-up points along the route, if there is any mail to be picked up at the individual points. One of the ground mechanisms will be provided for each pick-up point and will be arranged at an open point above which a plane may come down to the relatively low altitude necessary to pick up the article or package. The ground apparatus will be arranged in such position that the left hand end of the apparatus as viewed in Figure 1 heads into the wind to facilitate the safe flying of the pick-up plane at a relatively low altitude and at a reasonably slow speed, if desired.

When an article is to be picked up, the opera-' tor will set the lever mechanism by pushing the lower end of the lever arm to the left as viewed in Figure 2 to hook it behind the hook 9|, and this hook will remain in latched position by frictional engagement with the lever arm 80. Access to this lever arm may be had through a suitable hand hole in the side of the vehicle as indicated in Figure l, and if desired, a light spring may urge the right hand end of the lever 81 upwardly to latched position so that it merely will be necessary for the operator to move the lever arm 80 to the left to the latched position.

The catapult carriage 28 is then moved along its trackway to the right as viewed in Figure 2, whereupon the pivoted hook 83 will ride over and engage behind the detent hook 82, the catapult and the parts of the latch mechanism then occupying the position shown in Figure 2.

Either by removing the light masts 38 or by loosening the screws 50 to permit the masts and tubes 4| to turn in the supports 43, the upper ends of the masts will be accessible for the placing betweenthe switch arms 96 and I00 .of the:

rubber thimbles I03 (Figure 7). Thesethimbles are spaced a distance apart on the pick-up cable equal to the distance between the masts, as will be apparent. After the thimbles have been placed in position, the masts are returned to their normal position shown in Figure 3 and the feet 5| (Figure 5) are adjusted into contact with the surrounding ground to prevent the lateral swinging of the apparatus and particularly the masts. It will be understood that the setting of the various parts takes place with the manual switch I06 (Figure 8) in open position, otherwise the solenoid 04 will have been energized by the closing of the switches '96 and I00 prior to the placing of the rubber thimbles between these switch elements. After all of the parts of the apparatus have been set as described, the manual switch I06 is closed.

The operator may then operate a crank on the shaft II, or this shaft may be suitably power operated, to rotate the pinion I0 and thus rotate the gear 69 (Figure 2) to wind the belt 62 (Figure 10) on the Windlass pulley 68; During this operation the pawl 13 escapes over successive teeth of the ratchet wheel '12 and when th winding operation is completed, the ratchet mechanism prevents the unwinding of the strap 62. The shock cord 58 (Figure 1) is preferably of such length that when placed under its maximum tension with the heaviest loads on the catapult, the fitting BI (Figure 11) which connects the shock cord'55 to the strap 62 will reach not quite to the pulley 03, the parts under such conditions occupying the positions shown in Figure 11. The apparatus is adapted for the catapulting and picking up of Various loads and has been highly successful in operation for picking up loads as great as 100 pounds. The shock cord 56 will betensioned according to the load to be projected, the greater tensioning obviously being employed for heavier loads in order to overcome the inertia of the catapult carriage of each individual load to impart the desired speed of movement to the article to be picked up. As a practical matter it has been demonstrated that the apparatus is operative for quite accurately projecting the articles at speeds corresponding to the speeds of the plane operating in connection with the mechanism.

The apparatus is now ready for the passage thereover of the pick-up plane and it will be obvious that since regular schedules for such planes can be readily established the ground mechanism will be set for operation in advance of the scheduled time of arrival of the plane. As the plane approaches the pick-up point, the arm I2 (Figure 1) which is normally folded up against the bottom of the fuselage of the plane, is lowered to the operative position shown in Figure 1 and advances over the apparatus with the hook I3 arranged at a level definitely below the level of the portion 39 of the pick-up loop which extends between the masts 38 as shown in Figure 3. As the plane continues its level flight at the height shown in Figure 1, the hook I3 will engage the loop portion 30 and exert a pull thereon in a generally horizontal direction. The switch arms 96 and I00 may be sloped upwardly slightly as shown in Figure 7 so that the horizontal force exerted by the pick-up hook will cause the thimbles I03 to exert a force tending to more readily open the switch arms I00 and thus release the thimbles. The sloping of the switch arms 96 and I00 need not be provided, however, since these arms may be horizontally arranged for the direct pulling of the thimbles I03 from" between the switch arms.

Both thimbles I03 will be pulled from between their associated switch arms, but obviously one will usually be dislodged'an instant ahead'of the other. Upon" the releasing of either switch arm I00 the solenoid 94 will be immediately'energized since the circuits through the two sets of switch arms are in parallel as indicated in Figure 8. Accordingly it willbe apparent that as soon as the hook I3picksup the loop portion 30 and releases either of the switch arms I00, the solenoid 94will be energized to pull upwardly on the left hand end of the lever 81, as viewed in Figure 2, thus releasing the hook 9| from the lever arm 80, whereupon the spring 86 will rotate the bell crank lever 79in a counter-clockwise direction to release the detent 82 from the hook 83;

The catapult carriage accordingly will be released and the tensioned shock cord 56' immediately pulls the catapult cord to the leftas viewed in Figures 1 and 2, the tension of the shock cord beingsuffici'ent to overcome the inertia of the carriage 28 and the article 29 therein and to impart to both a speedapproximately equaling'the speed of the plane.

Of course, this releasing mechanism will be operated immediately upon the pulling of either rubber thimble I03 from its associated pair of switch arms 96 and I00 but the movement of the plane will almost immediately dislodge the other thimble I03 and the pick-up c'ord accordingly will be free of all p'artsof the apparatus. In other words, the pick-up cord at this time will be engaged by the hook I3 and willbe connected to the article, but willbe free from allparts of the operating mechanism ready to be picked up by the plane. The catapult trackway preferably slopes slightlyupwardly and thus the'artic'le is projected in the'directionof travel of the'plane and slightly upwardly. The purpose of this'will become apparent below.

The movement of the catapult carriage continues until it strikes the shock absorber comprising the elements I32, I33 and I34 (Figure 10) which cushions and stops the movement of the carriage. However, the inertia of the article'in the carriage will cause it to slide'from the carriage but will not retard it's speed of movement to any great extent. However, some slight retarding'will be caused and the article of course will lose velocity as it'travels from the carriage,

and the upward sloping of the trackway provides for a trajectory through which the article will travel which will be much longer before'it inter sects the ground than would be true of a horizontal trackway. The limit of the 'tra'jectorywill not be reached, however, since the plane will have taken up the slack in the pick-up cable prior to the engagement of the article with the round. In this connection it is pointed" out that immediately upon engagement of the hook I3 with the pick-up cable, the plane elevators will be operated to pick up altitude and thus suspend the article free of the ground.

By any suitable mechanism, not apart of the present invention, the hook I3 maybe pulled upwardly into the fuselage of the plane, thus providing access to the pick-up cable andenabling the operator of the plane to pull the article into the plane through the door provided for this purpose in the bottom of the fuselage.

After the article has been picked up, the ground operator may swing the handle 15 (Figure 10) to release the pawl 13 from the ratchet wheel 12, whereupon the strap I52 may be freely pulled to unwind it from the Windlass pulley 66 preparatory to the next setting of the apparatus.

The form of the invention shown in Figures 12 and 13 is similar in its operation to that previously described and need not be referred to in detail. Instead of providing switches at the upper ends of the masts, the single switchcomprising the elements I22 and I23 may be relied upon to close the circuit through the solenoid 94. The fork H9 is engageable with the cable section I38 afterthe pick-up cable as a Whole has been set for the pickup operation with the normal amount of slac'kin the portion of the pick-up cable between themasts and the article 29. This frictiona1 engagement of the fork I I9 with the cable section I38 will hold the switch element I22 approximately in the position shown in Figure 12.

As in the previous case, of course, the manual switch I29 will be left openuntil the apparatus is completely set and adjusted. After engaging the fork H9 with the cable section I38 the operator willadjust the screw I31 (Figure 13) to cause it to engage the extension I36 and move the arm I35. against the tension of the spring I34 until a suitable gap is provided between the switch contacts I22 and I23. The manual switch I29 is then closed.

When the pick-up hook I3 engages the cable section 39 between the masts, it will pull the pickup cable free of the switch elements 96 and I (Figure 7) which now act merely as holding elements and not switches. Upon the taking up of the slack in the cable, the section I38 (Figure 12) will be straightened out and thus will instantan'eously exert upward force on the fork II9 followed immediately by the pulling out of the cable section. from the fork. The momentary lifting of thefork H9 lowers thecontact I22 into engagement with the contact I23, thus closing the circuit through the solenoid 94 and releasing the catapult latch mechanism.

The catapult will be projected in the manner previously described. It will be apparent that the wiring element lllis relatively light and accordingly possesses little inertia. Its left end as viewed in Figure 12 is longer and slightly heavier than the other endiandimmediately upon the releasing of the fork I I9, the adjacent arm I I8 immediately tends to move downwardly and if it is not moved downwardly soon enough to clear the catapult carriage, this carriage will strike the arm II 8- and move'it downwardly. The member H5 being very light, this operation will not. damage this elementand will not retard the catapult carriage.

The advantage of the system shown in Figures 12 and 13 lies in its simplicity and the centralizing of all mechanical elements and control circuits in one end of the vehicle I4. The time element between the taking up of the slack in the pick-up cable, and the releasing of the catapult latch mechanism is negligible, practically no lag whatever being provided. This form of the mechanism is therefore adapted for the picking up of articles at plane speeds of 100 miles per hour, for example, but is not as well adapted for pickup operations at high plane speeds as is true of the form of the invention shown in Figures 1 to 11 inclusive.

From the foregoing itwill be apparent that the present apparatus is highly advantageous over pick-up mechanisms in which a plane is subjected to the sudden loading of the pick-up hook by an article at rest, the apparatus being practicable for use in picking up articles or packages weighing many times the weight which can be picked up by an apparatus in which no catapult is employed. The apparatus is highly advantageous over prior catapult mechanisms for the reason that it eliminates the use of relatively heavy, stiff and expensive masts and the mechanical means which must be associated therewith for releasing the catapult mechanism upon the swinging of the mast.

As previously stated, catapult pick-up mechanisms of the type shown in the prior patent of Bushmeyer and Card No. 1,892,381 have been highly successful in operation. However, the masts preferably are made of special alloy steels to possess the necessary strength and stiffness to be swung by the passing plane and the engagement of the hook thereof with the cable, and the masts must be strong enough to operate the rock shafts connected thereto and the crank and other mechanisms connected to the shafts for releasing the catapult latch mechanism. Moreover, the shafts and the releasing mechanisms connected to the cranks are relatively heavy and expensive to build. In addition, an apparatus of this character requires that the fork in which the cable portion 39 is arranged open upwardly so that horizontal movement of the plane will pull against one side of each fork to swing the associated mast.

This feature is disadvantageous because of the.

inertia of the parts which must be overcome by the airplane-carried hook before the catapult latch mechanism is released.

As distinguished from such an apparatus relatively cheap inexpensive masts may be employed and in fact these masts may be relatively fragile since they are not depended on to operate any of the release mechanism associated with the catapult. Therefore, the apparatus may be much more economically manufactured. In addition, the present apparatus permits the picking up of relatively heavy loads with substantially no horizontal drag on the plane since the latter is not called upon to overcome the inertia and effect the movement of relatively heavy parts in order to release the catapult latch mechanism. It will benoted that the fork elements which support the rubber thimbles, namely the arms 98 and I 93 may be faced in the direction of or nearly in the direction of movement of the plane instead of extending upwardly in accordance with prior practice, thus permitting the hook I3 to very easily dislodge the pick-up cable attached to the article in the catapult. As a matter of fact, where it was necessary to prevent the immediate release of the pick-up cable from the masts in order to operate the mechanism, the present mechanism depends for its operation on the easy releasing of the pick-up cable, thus substantially eliminating any drag on the pick-up plane.

It is to be understood that the forms of the invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement of parts may be resorted to as do .not depart from the spirit of the invention or the scope of the subjoined claims.

We claim: 7

1. An airplane pick-up mechanism comprising a catapult having anarticle carrier, a latch mechanism for holding the article carrier in a normal position, and tension means connected to the article carrier to move it in one direction upon the releasing of said latch mechanism, flexible means connected to an article in said carrier and having a loop portion, a pair of spaced masts each having a pair of fingers at its upper end to receive said loop portion therebetween and support it in a position to be engaged by a pick-up device on an aircraft traveling thereover in said direction, at least one finger of one pair being movable by said loop portion when the latter is pulled by said pick-up device, a solenoid energizable for releasing said latch mechanism, and means including and operatively connected to said movable finger to be operated thereby for energizing said solenoid upon the pulling of said loop portion by said pick-up device.

2. An airplane pick-up mechanism comprising a catapult having an article carrier, a latch mechanism for holding the article carrier in a normal position, and tension means connected to the article carrier to move it in one direction upon the releasing of said latch mechanism, flexible means connected to an article in said carrier and having a loop portion, a pair of spaced supports each having a pair of fingers at its upper end to receive said loop portion therebetween and support it in a position to be engaged by a pick-up device on an aircraft traveling thereover in said direction, a solenoid energizable for releasing said latch mechanism, and means including and connected to said fingers for energizing said solenoid upon movement of said portion of said flexible means incident to the exertion of a pull on said flexible means by said pick-up device.

3. An airplane pick-up mechanism comprising a catapult having an article carrier, a latch mechanism for holding the article carrier in a normal position, and tension means connected to the article carrier to move it in one direction upon the releasing of said latch mechanism, flexible means connected to an article in said carrier and having a loop portion, a pair of spaced masts each having a pair of fingers at its upper end extending generally in said direction to receive said loop portion therebetween and support it in a position to be engaged by a pickup device on an aircraft traveling thereover in said direction, a solenoid energizable for releasing said latch mechanism, and a circuit for said solenoid including a. pair of switch contacts formed by said fingers and normally held in open position by said flexible means and constructed and arranged to move to closed position upon the picking up of said flexible means by said pick-up device.

4. An airplane pick-up mechanism comprising a catapult having an article carrier, a latch mechanism for holding the article carrier in a normal position, and tension means connected to said article carrier to move it in one direction upon the releasing of said latch mechanism, flexible means connected to an article in said carrier and having a loop portion, a pair of spaced masts each having a pair of spaced fingers extending generally in said direction and adapted to receive said loop portion therebetween to support it in a position to be engaged by a pick-up device on an aircraft traveling thereover in said direction, one finger of each pair being movable and spring biased toward the other finger of each pair to releasably grip said flexible means, and electrically controlled means constructed and arranged to be operative upon movement of said movable finger toward the other finger when said loop portion is pulled from between aid fingers by said pick-up means,-

for releasing said latch mechanism.

5. An airplane pick-up mechanism comprising a catapult having an article carrier, a latch mechanism for holding the article carrier in a normal position, and tension means connected to said article carrier to move it in one direction upon the releasing of said latch mechanism,

flexible means connected to an article in saidcarrier and having a loop portion, a pair of spaced masts each having a pair of spaced fingers extending generally in said direction and adapted to receive said loop portion therebetween to support it in a position to be engaged by a pick-up device on an aircraft traveling thereover in said direction, one finger of each pair being movable and spring biased toward the other pair to releasably grip said flexible means, a solenoid energizable for releasing said latch mechanism, and a circuit for said solenoid including a pair of circuits connected in parallel and in which said pairs of fingers are respec tively arranged and constructed to operate as switches when the loop portion of said flexible means is pulled therefrom by said pick-up device.

6. A mast construction for a catapult-operated airplane pick-up mechanism wherein a pair of spaced vertical masts support the loop-of a flexible element connected to an article to be picked up and wherein such loop is engageable by a pick-up device on an airplane moving thereover in a direction perpendicular to the plane of said masts, comprising a mast element, and a pair of fingers carried by the upper end of said mast element and projecting therefrom at a substantial angle to the axis of the mast element and generally in the direction of travel of the airplane to facilitate the pulling of the loop from between said fingers, one of said fingers being movable toward and spring biased to contact with the other finger, said fingers having contactible metal portions to serve as an electric switch.

'7. An airplane pick-up mechanism comprising a catapult having an article carrier, a latch mechanism for holding the carrier in normal position, and means tending to project the article carrier in one direction, a pair of spaced stationary masts, a pair of fingers at the upper end of each mast, one pair of said fingers constituting a switch device biased to closed position, a flexible element connected to an article on the carrier and having a loop portion extending directly from the article to the masts and engaged by said pairs of fingers to be supported thereby, said pairs of fingers constituting the sole means contacting said loop, and electrical means for releasing said latch comprising a circuit including said switch device, the fingers constituting said switch device being normally held apart by the portion of the flexible element therebetween.

8. An airplane pick-up mechanism comprising a catapult having an article carrier and means operable for projecting the latter in one direction, a pair of spaced stationary masts, a flexible element connected to an article on the carrier and having a loop portion extending to said masts adjacent the tops thereof and across the space between said masts, means at the upper end of each mast for engaging and supporting said loop portion and constituting the sole means other than the article carrier which engages any portion of said flexible member, one of said supporting means comprising a pair of fingers biased towardeach other and normally held apart by the loop portion arranged therebetween, said fingers constituting a switch device operative when said loop portion is pulled therefrom by an airplane-carried element, and electrical means for rendering said carrier projecting means operative, and having a circuit including said switch device whereby such circuit will be closed immediately upon the picking up of said loop portion by the airplane-carried element.

9. An airplane pick-up mechanism comprising a catapult having an article carrier, and means for projecting the article in one direction, a pair of spaced stationary supports, a supporting device at the upper end of each support, one of said supporting devices constituting a switch device, a flexible element connected to an article on the carrier and having a loop portion extending directly from the article to said supports and engaged by said supporting devices to be supported thereby, said supporting devices constituting the sole means contacting said loop, and electrical means connected to said projecting means and to said switch device for rendering said projecting means operative immediately upon the pulling of said loop by an airplane-carried element.

JEANNOT G. INGRES. HENRY W. HEY. 

